The present invention relates to a semiconductor apparatus comprising a semiconductor device mounted on a wiring substrate. Moreover, this invention relates to a method of and apparatus for mounting a semiconductor-device.
When mounting a semiconductor device such as a flip chip or a BGA (Ball Grid Array) onto a wiring substrate, it is difficult to position the device against the wiring substrate while visually checking. The reason for this is that the functional electrode sections, such as bumps and conductor pads on the surface of the wiring substrate, which are to be connected to each other, are both hidden. If the semiconductor device is mounted on the wiring substrate in a misaligned position, the desired functioning cannot be expected from the semiconductor device and extensive repairs involving replacement will be required.
The following methods are known conventionally that try to solve the above problem. This is, a method wherein positioning slots (i.e., slots used when positioning is performed) or positioning projections (i.e., projections used when positioning is performed) are provided on the conductor pads of the wiring substrate, a method wherein the functional electrodes of the semiconductor device has special shapes, and a method wherein the misalignment is detected by placing a through-hole in the semiconductor device. However, these methods require separate manufacturing processes and different equipment for manufacturing the conductor pads plus the functional electrode section and for configuring the through-holes, causing the manufacturing costs to increase remarkably. Moreover, in the latter method, because the manufacturing process for making the through-holes differs from that for configuring the functional electrode sections of the semiconductor devices, misalignment of the through-holes and the functional electrode section is caused, with a possibility of decreasing the mounting accuracy of the semiconductor device.
Conventionally, there is also known a semiconductor device comprising misalignment-detection electrodes (i.e., electrodes used for detection of misalignment) near the functional electrode sections (see, for example, Japanese Laid Open Patent Application No. 10-335401). The misalignment of the misalignment-detection electrodes and the functional electrode sections is detected by determining whether there is electrical conductivity between the misalignment-detection electrodes and the conductor pads of the wiring substrate. In this method, there are advantages that the production cost does not increase or the mounting accuracy does not decrease due to misalignment of the functional electrodes and the misalignment-detection electrodes because the misalignment-detection electrodes can be configured with the same manufacturing process as that of the functional electrode section of the semiconductor device.
In the conventional art, when there is electrical conductivity between the misalignment-detection electrodes on the semiconductor device and the conductor pads on the wiring substrate, it is determined that there is misalignment in the semiconductor device and the wiring substrate. Conversely, when there is no electrical conductivity between the misalignment-detection electrodes on the semiconductor device and the conductor pads on the wiring substrate, it is determined that there is proper alignment between the semiconductor device and the wiring substrate. Obviously, misalignment cannot be detected when, for example, there is a loose connection between the misalignment-detection electrodes and the conductor pads. Moreover, a wrong detection determination that the semiconductor device and wiring substrate are positioned accurately can be made even when the connection is not loose, if, for example, the mounting position of the semiconductor device against the wiring substrate is misaligned greatly. As a result, even when there is misalignment in the semiconductor device and the wiring substrate, it cannot be corrected and repairs involving replacement will be required.
It is an object of this invention to provide a semiconductor apparatus, a method of and apparatus for mounting a semiconductor-device in which accurate and infallible detection as well as correction of misalignment in the semiconductor device and the wiring substrate can be made.
The semiconductor apparatus according to a one aspect of this invention comprises a wiring substrate and a semiconductor device to be mounted on the wiring substrate. Moreover, a pair of contact terminals provided in between the semiconductor device and the wiring substrate, which can come in electrical contact with each other. In addition, a pair of detection terminals on one of the semiconductor device and the wiring substrate in such a manner that they are spaced apart, or a pair of detection terminals placed separately on the semiconductor device and the wiring substrate. The contact terminal pairs are made to come in contact with each other when the semiconductor device is in line with the regular mounting position on the wiring substrate and there is an electrical conductivity between the detection terminals of the pair through these contact terminal pairs.
In the method of mounting a semiconductor-device on a wiring substrate according to another aspect of this invention, the semiconductor-device and the wiring substrate have a pair of contact terminals that come in electrical contact with each other when the semiconductor-device is mounted on a regular mounting position on the wiring substrate. The method comprises the step of positioning the semiconductor device on the wiring substrate according to the electrical conductivity between the pair of contact terminals due to a mutual contact between the pair of contact terminals.
In the apparatus for mounting a semiconductor-device on a wiring substrate according to still another aspect of this invention, the semiconductor-device and the wiring substrate have a pair of contact terminals that come in electrical contact with each other when the semiconductor-device is mounted on a regular mounting position on the wiring substrate. This apparatus comprises a determination unit which determines whether there is an electrical conductivity between the pair of contact terminals; a relative-position shifting-unit which alters the relative positions of the semiconductor-device and the wiring substrate; and a control unit which controls the relative-position shifting-unit to alter the relative positions of the semiconductor-device and the wiring substrate until the determination unit determine establishment of electrical conductivity between the pair of contact terminals.
Other objects and features of this invention will become apparent from the following description with reference to the accompanying drawings.